title: Live-cell visualization of dynamics of HIV budding site interactions with an ESCRT component.
abstract: HIV (human immunodeficiency virus) diverts the cellular ESCRT (endosomal sorting complex required for transport) machinery to promote virion release from infected cells. The ESCRT consists of four heteromeric complexes (ESCRT-0 to ESCRT-III), which mediate different membrane abscission processes, most importantly formation of intralumenal vesicles at multivesicular bodies. The ATPase VPS4 (vacuolar protein sorting 4) acts at a late stage of ESCRT function, providing energy for ESCRT dissociation. Recruitment of ESCRT by late-domain motifs in the viral Gag polyprotein and a role of ESCRT in HIV release are firmly established, but the order of events, their kinetics and the mechanism of action of individual ESCRT components in HIV budding are unclear at present. Using live-cell imaging, we show late-domain-dependent recruitment of VPS4A to nascent HIV particles at the host cell plasma membrane. Recruitment of VPS4A was transient, resulting in a single or a few bursts of at least two to five VPS4 dodecamers assembling at HIV budding sites. Bursts lasted for ∼35 s and appeared with variable delay before particle release. These results indicate that VPS4A has a direct role in membrane scission leading to HIV-1 release.
authors.affiliation: Physical Chemistry, Department of Chemistry and Biochemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for NanoScience, Ludwig-Maximilians-Universität München, Butenandtstrasse 11, 81377 Munich, Germany.
authors.forename: Viola
authors.initials: V
authors.lastname: Baumgärtel
authors.forename: Sergey
authors.initials: S
authors.lastname: Ivanchenko
authors.forename: Aurélie
authors.initials: A
authors.lastname: Dupont
authors.forename: Mikhail
authors.initials: M
authors.lastname: Sergeev
authors.forename: Paul W
authors.initials: PW
authors.lastname: Wiseman
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Kräusslich
authors.forename: Christoph
authors.initials: C
authors.lastname: Bräuchle
authors.forename: Barbara
authors.initials: B
authors.lastname: Müller
authors.forename: Don C
authors.initials: DC
authors.lastname: Lamb
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D002462:Cell Membrane / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism*; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000378:metabolism; D057074:Virus Release / Q000502:physiology*
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D015683:Gene Products, gag; D011993:Recombinant Fusion Proteins; D025262:Vacuolar Proton-Translocating ATPases; D000074183:ATPases Associated with Diverse Cellular Activities; C490305:VPS4A protein, human